Editors Gerhard Knothe National Center for Agricultural Utilization Research Agricultural Research Service U.S. Department of Agriculture Peoria, Illinois, U.S.A. Jon Van Gerpen Department of Mechanical Engineering Iowa State University Ames, Iowa, U.S.A. Jürgen Krahl University of Applied Sciences Coburg, Germany Champaign, Illinois The Biodiesel Handbook Biodiesel FM(1-0)(Final)22 Nov 6/6/05 3:51 PM Page 1 Copyright © 2005 AOCS Press AOCS Mission Statement To be the global forum for professionals interested in lipids and related materials through the exchange of ideas, information science, and technology. AOCS Books and Special Publications Committee M. Mossoba, Chairperson, U.S. Food and Drug Administration, College Park, Maryland R. Adlof, USDA, ARS, NCAUR, Peoria, Illinois P. Dutta, Swedish University of Agricultural Sciences, Uppsala, Sweden T. Foglia, ARS, USDA, ERRC, Wyndmoor, Pennsylvania V. Huang, Abbott Labs, Columbus, Ohio L. Johnson, Iowa State University, Ames, Iowa H. Knapp, Deanconess Billings Clinic, Billings, Montana D. Kodali, General Mills, Minneapolis, Minnesota T. McKeon, USDA, ARS, WRRC, Albany, California R. Moreau, USDA, ARS, ERRC, Wyndoor, Pennsylvania A. Sinclair, RMIT University, Melbourne, Victoria, Australia P. White, Iowa State University, Ames, Iowa R. Wilson, USDA, REE, ARS, NPS, CPPVS, Beltsville, Maryland Copyright (c) 2005 by AOCS Press. All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means without written permission of the publisher. The paper used in this book is acid-free and falls within the guidelines established to ensure permanence and durability. Library of Congress Cataloging-in-Publication Data Biodiesel : etc / editor, Author. p. cm. Includes bibliographical references and index. ISBN 0-000000-00-00 (acid-free paper) 1. XXXX. 2. XXXXX. 3. XXXX. I. Author(s). TP991.S6884 2004 668'.12 dc22 2004008574 CIP Printed in the United States of America. 08 07 06 05 04 5 4 3 2 1 Biodiesel FM(1-0)(Final)22 Nov 6/6/05 3:51 PM Page 2 Copyright © 2005 AOCS Press P r e f a c e The technical concept of using vegetable oils or animal fats or even used oils as a renew- able diesel fuel is a fascinating one. Biodiesel is now the form in which these oils and fats are being used as neat diesel fuel or in blends with petroleum-based diesel fuels. The concept itself may appear simple, but that appearance is deceiving since the use of biodiesel is fraught with numerous technical issues. A c c o r d i n g l y, many researchers around the world have dealt with these issues and in many cases devised unique solutions. This book is an attempt to summarize these issues, to explain how they have been dealt with, and to present data and technical information. Countless legisla- tive and regulatory efforts around the world have helped pave the way toward the wide- spread application of the concept. This book addresses these issues also. To complete the picture, chapters on the history of vegetable oil-based diesel fuels, the basic concept of the diesel engine, and glycerol, a valuable byproduct of biodiesel production, are included. We hope that the reader may find the information in this book useful and stimulat- ing and that most of the significant issues regarding biodiesel are adequately addressed. If a reader notices an error or inconsistency or has a suggestion to improve a possible future edition of this book, he or she is encouraged to contact us. This book has been compiled from the contributions of many authors, who gra- ciously agreed to do so. We express our deepest appreciation to all of them. We also sin- cerely thank the staff of AOCS Press for their professionalism and cooperation in bring- ing the book to print. Gerhard Knothe Jon Van Gerpen J ü rge n Krahl November 4, 2004 Biodiesel FM(1-0)(Final)22 Nov 6/6/05 3:51 PM Page 3 Copyright © 2005 AOCS Press Contributing Au t h o r s Gerhard Knothe, USDA, ARS, NCAUR, Peoria, IL 61604 Jon Van Gerpen, Department of Mechanical Engineering, Iowa State University, Ames, IA 50011 Michael J. Haas, USDA, ARS, ERRC, Wyndmoor, PA 19038 Thomas A. Foglia, USDA, ARS, ERRC, Wyndmoor, PA 19038 Robert O. Dunn, USDA, ARS, NCAUR, Peoria, IL 61604 Heinrich Prankl, BLT–Federal Institute of Agricultural Engineering, A 3250 Wieselburg, Austria Leon Schumacher, Department of Biological Engineering, University of Missouri- Columbia, Columbia, MO 65211 C.L. Peterson, Department of Biological and Agricultural Engineering (Emeritus), University of Idaho, Moscow, ID 83844 Gregory Möller, Department of Food Science and Technology, University of Idaho, Moscow, ID 83844 Neil A. Bringe, Monsanto Corporation, St. Louis, MO 63167 Robert L. McCormick, National Renewable Energy Laboratory, Golden, CO 80401 Teresa L. Alleman, National Renewable Energy Laboratory, Golden, CO 80401 Jürgen Krahl, University of Applied Sciences, Coburg, Germany Axel Munack, Institute of Technology and Biosystems Engineering, Federal Agricultural Research Center, Braunschweig, Germany Olaf Schröder, Institute of Technology and Biosystems Engineering, Federal Agricultural Research Center, Braunschweig, Germany Hendrik Stein, Institute of Technology and Biosystems Engineering, Federal Agricultural Research Center, Braunschweig, Germany Jürgen Bünger, Center of Occupational and Social Medicine, University of Göttingen, Göttingen, Germany Steve Howell, MARC-IV Consulting Incorporated, Kearney, MO 64060 Joe Jobe, National Biodiesel Board, Jefferson City, MO 65101 Dieter Bockey, Union for Promoting Oilseed and Protein Plants, 10117 Berlin, Germany Biodiesel FM(1-0)(Final)22 Nov 6/6/05 3:51 PM Page 5 Copyright © 2005 AOCS Press Jürgen Fischer, ADM/Ölmühle Hamburg, Hamburg, Germany Werner Körbitz, Austrian Biofuels Institute, Vienna, Austria Sven O. Gärtner, IFEU-Institute for Energy and Environmental Research, Heidelberg, Germany Guido A. Reinhardt, IFEU-Institute for Energy and Environmental Research, Heidelberg, Germany Donald B. Appleby, Procter & Gamble Chemicals, Cincinnati, OH 45241 Biodiesel FM(1-0)(Final)22 Nov 6/6/05 3:51 PM Page 6 Copyright © 2005 AOCS Press Contents Preface Contributing Authors 1 Introduction Gerhard Knothe 2 The History of Vegetable Oil-Based Diesel Fuels Gerhard Knothe 3 The Basics of Diesel Engines and Diesel Fuels Jon Van Gerpen 4 Biodiesel Production 4.1 Basics of the Transesterification Reaction Jon Van Gerpen and Gerhard Knothe 4.2 Alternate Feedstocks and Technologies for Biodiesel Production Michael J. Haas and Thomas A. Foglia 5 Analytical Methods for Biodiesel Gerhard Knothe 6 Fuel Properties Gerhard Knothe 6.1 Cetane Numbers–Heat of Combustion–Why Vegetable Oils and Their Derivatives Are Suitable as a Diesel Fuel Gerhard Knothe 6.2 Viscosity of Biodiesel Gerhard Knothe 6.3 Cold Weather Properties and Performance of Biodiesel Robert O. Dunn 6.4 Oxidative Stability of Biodiesel 6.4.1 Literature Overview Gerhard Knothe Biodiesel FM(1-0)(Final)22 Nov 6/6/05 3:51 PM Page 7 Copyright © 2005 AOCS Press 6.4.2 Stability of Biodiesel Heinrich Prankl 6.5 Biodiesel Lubricity Leon Schumacher 6.6 Biodiesel Fuels: Biodegradability, Biological and Chemical Oxygen Demand, and Toxicity C.L. Peterson and Gregory Möller 6.7 Soybean Oil Composition for Biodiesel Neal A. Bringe 7 Exhaust Emissions 7.1 Effect of Biodiesel Fuel on Pollutant Emissions from Diesel Engines Robert L. McCormick and Teresa L. Alleman 7.2 Influence of Biodiesel and Different Petrodiesel Fuels on Exhaust Emissions and Health Effects Jürgen Krahl, Axel Munack, Olaf Schröder, Hendrik Stein, and Jürgen Bünger 8 Current Status of the Biodiesel Industry 8.1 Current Status of Biodiesel in the United States Steve Howell and Joe Jobe 8.2 Current Status of Biodiesel in the European Union Dieter Bockey 8.2.1 Biodiesel Quality Management: The AGQM Story Jürgen Fischer 8.3 Status of Biodiesel in Asia, the Americas, Australia, and South Africa Werner Körbitz 8.4 Environmental Implications of Biodiesel (Life-Cycle Assessment) Sven O. Gärtner and Guido A. Reinhardt 8.5 Potential Production of Biodiesel Charles L. Peterson 9 Other Uses of Biodiesel Gerhard Knothe 10 Other Alternative Diesel Fuels from Vegetable Oils Robert O. Dunn Biodiesel FM(1-0)(Final)22 Nov 6/6/05 3:51 PM Page 8 Copyright © 2005 AOCS Press 11 Glycerol Donald B. Appleby Appendix A: Technical Tables Appendix B: Biodiesel Standards Appendix C: Internet Resources Biodiesel FM(1-0)(Final)22 Nov 6/6/05 3:51 PM Page 9 Copyright © 2005 AOCS Press 1 I n t ro d u c t i o n Gerhard Knothe Introduction: What Is Biodiesel? The major components of vegetable oils and animal fats are triacylglycerols (TAG; often also called triglycerides). Chemically, TAG are esters of fatty acids (FA) with glycerol (1,2,3-propanetriol; glycerol is often also called glycerine; see Chapter 11). The TAG of vegetable oils and animal fats typically contain several different FA. Thus, different FA can be attached to one glycerol backbone. The different FA that are contained in the TAG comprise the FA profile (or FA composition) of the vegetable oil or animal fat. Because different FA have different physical and chemical proper- ties, the FA profile is probably the most important parameter influencing the corre- sponding properties of a vegetable oil or animal fat. To obtain biodiesel, the vegetable oil or animal fat is subjected to a chemical reac- tion termed t r a n s e s t e r i f i c a t i o n. I n that reaction, the vegetable oil or animal fat is react- ed in the presence of a catalyst (usually a base) with an alcohol (usually methanol) to give the corresponding alkyl esters (or for methanol, the methyl esters) of the FA mix- ture that is found in the parent vegetable oil or animal fat. Figure 1 depicts the transes- terification reaction. Biodiesel can be produced from a great variety of feedstocks. These feed- stocks include most common vegetable oils (e.g., soybean, cottonseed, palm, peanut, rapeseed/canola, sunflower, safflower, coconut) and animal fats (usually tallow) as well as waste oils (e.g., used frying oils). The choice of feedstock depends largely on geography. Depending on the origin and quality of the feed- stock, changes to the production process may be necessary. Biodiesel is miscible with petrodiesel in all ratios. In many countries, this has led to the use of blends of biodiesel with petrodiesel instead of neat biodiesel. It is important to note that these blends with petrodiesel are not biodiesel. Often blends with petrodiesel are denoted by acronyms such as B20, which indicates a blend of 20% biodiesel with petrodiesel. Of course, the untransesterified vegetable oils and animal fats should also not be called “biodiesel.” Methanol is used as the alcohol for producing biodiesel because it is the least expensive alcohol, although other alcohols such as ethanol or i s o-propanol may yield a biodiesel fuel with better fuel properties. Often the resulting products are also called fatty acid methyl esters (FAME) instead of biodiesel. Although other alcohols can by definition yield biodiesel, many now existing standards are designed in such a fashion that only methyl esters can be used as biodiesel if the standards are observed correctly. Ch1(Biodiesel)(1-3)(Final) 6/6/05 3:22 PM Page 1 Copyright © 2005 AOCS Press Biodiesel has several distinct advantages compared with petrodiesel in addi- tion to being fully competitive with petrodiesel in most technical aspects: • Derivation from a renewable domestic resource, thus reducing dependence on and preserving petroleum. • Biodegradability. • Reduction of most exhaust emissions (with the exception of nitrogen oxides, NO x ). • Higher flash point, leading to safer handling and storage. • Excellent lubricity, a fact that is steadily gaining importance with the advent of low-sulfur petrodiesel fuels, which have greatly reduced lubricity. Adding biodiesel at low levels (1–2%) restores the lubricity. Some problems associated with biodiesel are its inherent higher price, which in many countries is offset by legislative and regulatory incentives or subsidies in the form of reduced excise taxes, slightly increased NO x exhaust emissions (as mentioned above), stability when exposed to air (oxidative stability), and cold flow properties that are especially relevant in North America. The higher price can also be (partially) offset by the use of less expensive feedstocks, which has sparked interest in materials such as waste oils (e.g., used frying oils). Why Are Vegetable Oils and Animal Fats Transesterified to Alkyl Esters (Biodiesel)? The major reason that vegetable oils and animal fats are transesterified to alkyl esters (biodiesel) is that the kinematic viscosity of the biodiesel is much closer to Fig. 1. The transesterification reaction. R is a mixture of various fatty acid chains. The alcohol used for producing biodiesel is usually methanol (R′ = CH 3 ). Ch1(Biodiesel)(1-3)(Final) 6/6/05 3:22 PM Page 2 Copyright © 2005 AOCS Press [...]... conferences in 1980 and 1981 (39–41) and marks the beginning of the rediscovery and eventual commercialization of biodiesel A final thought should be given to the term biodiesel itself A Chemical Abstracts search (using the “SciFinder” search engine with biodiesel as the key word) yielded the first use of the term biodiesel in the technical literature in a Chinese paper published in 1988 (111) The next... determined by the mixing of the fuel and air This period is known as mixing-controlled combustion The heterogeneous fuel-air mixture in the cylinder during the diesel combustion process contributes to the formation of soot particles, one of the most difficult challenges for diesel engine designers These particles are formed in high-temperature regions of the combustion chamber in which the air-fuel ratio... fuel-rich and consists mostly of carbon with small amounts of hydrogen and inorganic compounds Although the mechanism is still not understood, biodiesel reduces the amount of soot produced and this appears to be associated with the bound oxygen in the fuel (3) The particulate level in the engine exhaust is composed of these soot particles along with high-molecular-weight hydrocarbons that adsorb to the. .. starting the Copyright © 2005 AOCS Press Ch3 (Biodiesel) (1 7-2 5)(Final) 6/6/05 3:27 PM Page 18 engine under cold conditions The power of the engine is controlled by varying the volume of fuel injected into the cylinder; thus, there is no need for a throttle Figure 1 shows a cross section of the diesel combustion chamber with the fuel injector positioned between the intake and exhaust valves The timing of the. .. according to the biography by Nitske and Wilson.) Diesel states in these papers (4,5) that “at the Paris Exhibition in 1900 there was shown by the Otto Company a small Diesel engine, which, at the request of the French Government, ran on Arachide (earth-nut or pea-nut) oil, and worked so smoothly that only very few people were aware of it The engine was constructed for using mineral oil, and was then worked... from those of the spark-ignited engines that dominate the U.S passenger car market In a sparkignited engine, fuel and air that are close to the chemically correct, or stoichiomet ric, mixture are inducted into the engine cylinder, compressed, and then ignited by a spark The power of the engine is controlled by limiting the quantity of fuel-air mixture that enters the cylinder using a flow-restricting... some cases, the power loss may be even less than this because biodiesel s higher viscosity can decrease the amount of fuel that leaks past the plungers in the diesel fuel injection pump, leaving more fuel to be injected Tests showed that the actual efficiency at which the energy in the fuel is converted to power is the same for biodiesel and petroleum-based diesel fuel (11) Therefore, the brake specific... Howell, and J Jobe, The Effect of Biodiesel Fuels on Transient Emissions from Modern Diesel Engines, Part I Regulated Emissions and Performance, SAE Paper No 200 0-0 1-1 967, 2000 5 Tat, M.E., J.H Van Gerpen, S Soylu, M Canakci, A Monyem, and S Wormley, The Speed of Sound and Isentropic Bulk Modulus of Biodiesel at 21°C from Atmospheric Pressure to 35 MPa, J Am Oil Chem Soc 77: 285–289 (2000) 6 Knothe, G.,... the requirements of a diesel fuel and how biodiesel can be considered a desirable substitute, it is important to understand the basic operating principles of the diesel engine This chapter describes these principles, particularly in light of the fuel used and the ways in which biodiesel provides advantages over conventional petroleum-based fuels Diesel Combustion The operating principles of diesel...Ch1 (Biodiesel) ( 1-3 )(Final) 6/6/05 3:22 PM Page 3 that of petrodiesel The high viscosity of untransesterified oils and fats leads to operational problems in the diesel engine such as deposits on various engine parts Although there are engines and burners that can use untransesterified oils, the vast majority of engines require the lower-viscosity fuel Why Can Vegetable Oils and Animal Fats and Their . Fuels Gerhard Knothe 3 The Basics of Diesel Engines and Diesel Fuels Jon Van Gerpen 4 Biodiesel Production 4.1 Basics of the Transesterification Reaction Jon Van Gerpen and Gerhard Knothe 4.2 Alternate. Press for their professionalism and cooperation in bring- ing the book to print. Gerhard Knothe Jon Van Gerpen J ü rge n Krahl November 4, 2004 Biodiesel FM( 1-0 )(Final)22 Nov 6/6/05 3:51 PM. of the publisher. The paper used in this book is acid-free and falls within the guidelines established to ensure permanence and durability. Library of Congress Cataloging-in-Publication Data Biodiesel